1. Field
Aspects of the present invention relate to a secondary battery and a manufacturing method of the same, and more particularly, to a secondary battery and a manufacturing method of the same to form a remainder of an extended tape and compressing the remainder by a press outside a lower surface of the electrode assembly.
2. Description of the Related Art
Generally, a primary battery is not rechargeable, while a secondary battery is a rechargeable battery and is used in various portable electronic devices, such as a mobile phone, a notebook computer, and a camcorder. Examples of the secondary batteries include a nickel-cadmium secondary battery, a nickel-hydride secondary battery, a lithium-ion secondary battery, etc. The lithium-ion secondary battery has a greater operating voltage and energy density per unit of weight than those of the nickel-cadmium secondary battery and the nickel-hydride secondary battery, and therefore has been widely used as compared to other secondary batteries.
Secondary batteries are classified into a cylindrical battery, a square-shaped battery, and a pouch type battery, based on a shape of a battery case. In the cylindrical and square-shaped battery, an electrode assembly is included inside a cylindrical or square-shaped case. In the pouch type battery, an electrode assembly is included inside a pouch type case.
The electrode assembly is formed by winding an electrode assembly having a stacked structure of a negative sheet, a separator, and a positive sheet. A sealing tape is used to maintain a winding state of the electrode assembly and to protect the electrode assembly. Generally, the sealing tape is wrapped entirely around an outer circumferential surface of the electrode assembly. After wrapping the side surface of the electrode assembly with a side tape, the sealing tape fixes the side tape to the side surface of the electrode assembly through a thermocompression process. An additional lower tape is attached to a lower portion of the electrode assembly to prevent the lower portion of the electrode assembly from being exposed through a thermocompression process.
However, if excessive pressure is applied when attaching the lower tape, a lower portion of the separator is pushed up, and the lower portion of the electrode assembly may be damaged due to an external shock. In addition, if low pressure is applied when attaching the lower tape, the electrode assembly becomes thick due to the lower tape, and interference with a case may occur or the electrode assembly may be damaged when the electrode assembly is inserted into the case.